1. Field of the Invention
The invention relates generally to radio-frequency identification (RFID) tags. More particularly, the invention relates to devices and methods for sealing, protecting, and securing RFID tags on assets in the oil and gas industry.
2. Background of the Invention
A radio-frequency identification (RFID) tag is a device attached to, or incorporated into, an object to enable relatively easy and quick identification of the object using radiowaves. Most RFID tags contain at least two parts, an integrated circuit for storing and processing information related to the object to which the tag is attached, and an antenna for receiving and transmitting a signal carrying such information. The information regarding the object is acquired by an RFID reader that may be carried by a user and scanned over or aimed at the tag. Some RFID tags can be read with an RFID reader from a several meters away and/or outside the line of sight of the reader, thereby enhancing the speed and ease with which the object and select characteristics of the object may be identified. For use with goods and products, RFID tags are typically attached to the outside of the object in a location where it can be sufficiently read by an RFID reader.
In general, RFID tags come in three general varieties: passive, active, or semi-passive (also known as battery-assisted). Passive tags require no internal power source, thus being pure passive devices (i.e., they are only active when a reader is nearby to power them), whereas semi-passive and active tags require a power source, usually a small battery. To communicate, RFID tags respond to queries from the RFID reader by generating response signals read by the RFID reader that contain the information about the object to which the RFID tag is attached.
Most conventional RFID tags are designed for use in relatively mild environments such as in retail stores, in vehicles for electronic toll collection, etc. In many cases, the RFID tag is simply attached to the object to be identified with an adhesive or sticker. In addition, many conventional RFID tags are only readable with an RFID reader, as opposed to being visible to a naked eye. In other words, the information regarding the object is not visible, but rather, is contained exclusively in the signal generated by the RFID tag and read by the RFID reader.
In most oil and gas industry applications, the environmental conditions experienced by RFID tags tend to be relatively harsh. For instance, RFID tags are commonly exposed to temperature extremes, corrosive fluids and moisture, vibrations and impact loads. Such conditions can result in degradation and/or damage to conventionally unprotected and unsecured RFID tags. In some cases, the coupling between the RFID tag to the object may wear away or be overcome by vibrations and/or impact loads, resulting in the RFID tag becoming completely separated from the object for which it was intended. Moreover, in some situations, it may be desirable to visually identify the object in the field when an RFID reader is not readily accessible.
Accordingly, there remains a need in the art for RFID tags particularly adapted for use in relatively harsh, rugged environments likely to be experienced in the oil and gas industry. Such RFID tags would be particularly well received if they offered the potential for improved durability, a more reliable and secure coupling to the object, and direct visualization identification in such harsh environments.